source: git/Singular/ndbm.h @ 60dcbbc

#ifndef NDBM_H
#define NDBM_H
/****************************************
*  Computer Algebra System SINGULAR     *
****************************************/
/* $Id$ */
/*
* ABSTRACT: DBM
*/

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ndbm.h      5.1 (Berkeley) 5/30/85
 *
 * Par. 3 removed due to a license change (1999)
 * see ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
 */

/*
 * Hashed key data base library.
 */
#define PBLKSIZ 1024

#define DBLKSIZ 4096

typedef struct {
        int     dbm_dirf;               /* open directory file */
        int     dbm_pagf;               /* open page file */
        int     dbm_flags;              /* flags, see below */
        long    dbm_maxbno;             /* last ``bit'' in dir file */
        long    dbm_bitno;              /* current bit number */
        long    dbm_hmask;              /* hash mask */
        long    dbm_blkptr;             /* current block for dbm_nextkey */
        int     dbm_keyptr;             /* current key for dbm_nextkey */
        long    dbm_blkno;              /* current page to read/write */
        long    dbm_pagbno;             /* current page in pagbuf */
        char    dbm_pagbuf[PBLKSIZ];    /* page file block buffer */
        long    dbm_dirbno;             /* current block in dirbuf */
        char    dbm_dirbuf[DBLKSIZ];    /* directory file block buffer */
} DBM;

#define _DBM_RDONLY     0x01    /* data base open read-only */
#define _DBM_IOERR      0x02    /* data base I/O error */

#define dbm_rdonly(db)  ((db)->dbm_flags & _DBM_RDONLY)

#define dbm_error(db)   ((db)->dbm_flags & _DBM_IOERR)
        /* use this one at your own risk! */
#define dbm_clearerr(db)        ((db)->dbm_flags &= ~_DBM_IOERR)

/* for flock(2) and fstat(2) */
#define dbm_dirfno(db)  ((db)->dbm_dirf)
#define dbm_pagfno(db)  ((db)->dbm_pagf)

typedef struct {
        char    *dptr;
        int     dsize;
} datum;

/*
 * flags to dbm_store()
 */
#define DBM_INSERT      0
#define DBM_REPLACE     1

DBM     *dbm_open(char *file, int flags, int mode);
void    dbm_close(DBM *db);
datum   dbm_fetch(register DBM *db, datum key);
datum   dbm_firstkey(DBM *db);
datum   dbm_nextkey(register DBM *db);
long    dbm_forder(register DBM *db, datum key);
int     dbm_delete(register DBM *db, datum key);
int     dbm_store(register DBM *db, datum key, datum dat, int replace);

#endif /* NDBM_H */